the Echinodevmata of the Arctic Expedition. 461 



Although our knowledge of marsupiation in Echinoderms 

 has recently been largely augmented by the additional in- 

 stances which Sir Wyville Thomson records as occumng in 

 species from southern seas *, it is most interesting to find 

 so special an adaptation for the purpose in this truly arctic 

 asteroid. 



Two specimens only were obtained, being dredged by Mr. 

 Hart in Dobbin Bay. They measure about 60 millims. in 

 their greatest diameter. 



Ophiuroidea, 



Ophioglypha Sarsii (Liitken), Lyman. 



? Asterias ophmra, Dewliurst, Nat. Hist. Cetacea &c. Arctic Regions, 



p. 283, 1834. 

 Ophiura texturata, Forbes, pars (Append. Sutherland's Journal). 

 Ophiolepis ciliata, Sars, pars, Reise i Lofoten og Finmarken, p. 39 ; 



Stimpson, Invert, of Grand Manan, Smiths. Contrib. vi. p. 13. 

 Ophiura actifera, Agassiz, Proc. Am. Acad. 1851, p. 269 (no descr.). 

 O. coriacea, lAitken, Vidensk. Meddelelser, Nov. 1854, p. 101. 

 O. arctica ?, id. ibid. 



O. Sarsii, id. ibid., et Add. ad Hist. Ophiuridarum, p. 42. 

 Ophior/h/pha Sarsii, Lyman, 111. Cat. Mus. Comp. Zool. Harvard, i. 



p. 41 • Ljungman, Oph. Viv., CEfv. K. Vet.-Akad. Forh. 1866, p. 307. 



Coll. Feilden : Floeberg Beach, 10 fms. ; Discovery Bay, 

 25 fms. ; Hayes Point. 



An Ophioghjpha with mouth-shields shield-shaped, longer 

 than broad ; length less than, or only equal to, their distance 

 from the margin of the disk. Papilla3 of the disk-incision 

 about fifteen, and rather broad. IJnder arm-plates widely 

 separate, of a very broad, short triangle-shape. Two tentacle- 

 scales. No infrabrachial indentations. Spines rather long, 

 equal in length to tlie side arm-plates. 



This is the most northerly cchinoderm brought home by the 

 expedition, a fine specimen with a disk-diameter of 26 millims. 

 having been taken by Capt. Feilden at the winter quarters 

 of H.M.S. ' Alert,' in N. lat. 82° 27'. Other examples of 

 this species were obtained at Discovery Bay, and among 

 them one which is provided with remarkably long arm-spines, 

 being in relative proportion fully twice the length of the 

 spines generally occurring in 0. Sarsii. In this individual 

 the three spines ol' the sixth joint measure respectively 2*45 

 millims., 2'25 millims., 1*4 millim., the under arm-plate 

 being •? millim. long, tlie arm-joint 1 millim., and the disk- 

 diameter 15 millims. The remaining features of the specimen 

 agree too closely with thccharacters of 0. Sarsii (Llitk.), Lym., 



* Wyville Thomson, Joiirn. Linn. Soc. vol. xiii. p. oo. 



